[doc] Fix PMD Version in sidebar

docs/_data/sidebars/pmd_sidebar.yml

@@ -4,7 +4,7 @@
 entries:
 - title: sidebar
   product: PMD Project
-  version: 6.0.0
+  version: "!PMD_VERSION!"
   folders:
 
   - title:

docs/_includes/sidebar.html

@@ -1,7 +1,7 @@
 {% include custom/sidebarconfigs.html %}
 
 <ul id="mysidebar" class="nav">
-    <li class="sidebarTitle">{{sidebar[0].product}} {{sidebar[0].version}}</li>
+    <li class="sidebarTitle">{{sidebar[0].product}} {{sidebar[0].version | replace: '!PMD_VERSION!', site.pmd.version}}</li>
     {% for entry in sidebar %}
     {% for folder in entry.folders %}
     {% if folder.output contains "web" %}